From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-22.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC3FAC433E0 for ; Thu, 18 Jun 2020 09:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B86D421BE5 for ; Thu, 18 Jun 2020 09:32:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tRJULurj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729200AbgFRJcG (ORCPT ); Thu, 18 Jun 2020 05:32:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729187AbgFRJcC (ORCPT ); Thu, 18 Jun 2020 05:32:02 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C5D6C0613ED for ; Thu, 18 Jun 2020 02:32:01 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id w9so5882729ybt.2 for ; Thu, 18 Jun 2020 02:32:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=tjAwEnOyA0tmPVPrOK6icwtI4Nv9CgkoPBXdv/shKX8=; b=tRJULurj8Sxkc+zLSK2XRPE/sJzXm2gi8Rw1ZetD+yF0N3p/k4ToxNkfafXK66XSAd TpcTuaBAJ+ou389KAKOrIX+vOyqrO4gy1J2U/SwvqOZ+i4yhI/CWQ2ugaJO7ZCuSdumP DXmMjiHenxaWSbm2MuLVE42jRR5c9rCbmgCd9AuwSrCozlnyODuWZhdy0aGFPX/EWD13 2d7SoFzCnxlZn3ggvOr36Qy18Dst6mP6Nlr57sfBkOINPZhJn79bBRPFcC7OyZumU/Cs JemPE5rgdFQiju2YJJjCueVLGIbJjMMvDxEzGGXWmaN3xdFfNwp8BPmCar1n1ickxF7V zT7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=tjAwEnOyA0tmPVPrOK6icwtI4Nv9CgkoPBXdv/shKX8=; b=WNX0JOw2wfjL8C86bSEJFPut1YWRsv6BxmvJVo3p978jR/DOUzBYLltw0wggPGdfiw Ctcy8GHol2xNT7gDPlFJeEX6Qeih3UkwpqwG8SGedtM9R3zgD4CWRqO2vY8fMNvGmnDq A3s+wk47O7E1fISGFFbBwHIeO2fiSveAjOSAVtbYCJeuzRAQg0zpUzBqjM/dn2MSVVRL 5QruJ+WkyegwGcXSVnKjDBqWM4xQJVfyMnMm1SEmE9/PHqcPYDK6hrOHgsLtAPSH04Sb TUlTJxX0Uo6MRqBYfUAVGJzO3KX2CJaHvM4n6FNlfq3J0nJwv+5SmLHZqEvb972e6X/j MXtQ== X-Gm-Message-State: AOAM531cA0L9KVcnG6JGmJuibYaDGA3y0VJzqwkPNGKnPSMwqeQUudez ynp57HTAK9kincEG8QENoAZT18EK/Q== X-Google-Smtp-Source: ABdhPJwy9+aGQsiKvvd+I3hP4gMIO0df63d901PgqqfbNUqvP+Ko0eicVQzJDje94jgUPcEfbg9b3Vo2EA== X-Received: by 2002:a25:be02:: with SMTP id h2mr5002260ybk.315.1592472720343; Thu, 18 Jun 2020 02:32:00 -0700 (PDT) Date: Thu, 18 Jun 2020 11:31:16 +0200 In-Reply-To: <20200618093118.247375-1-elver@google.com> Message-Id: <20200618093118.247375-2-elver@google.com> Mime-Version: 1.0 References: <20200618093118.247375-1-elver@google.com> X-Mailer: git-send-email 2.27.0.290.gba653c62da-goog Subject: [PATCH 1/3] kcsan: Re-add GCC as a supported compiler From: Marco Elver To: elver@google.com, paulmck@kernel.org Cc: will@kernel.org, peterz@infradead.org, bp@alien8.de, tglx@linutronix.de, mingo@kernel.org, dvyukov@google.com, cai@lca.pw, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, Martin Liska Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org GCC version 11 recently implemented all requirements to correctly support KCSAN: 1. Correct no_sanitize-attribute inlining behaviour: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4089df8ef4a63126b0774c39b6638845244c20d2 2. --param=tsan-distinguish-volatile https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ab2789ec507a94f1a75a6534bca51c7b39037ce0 3. --param=tsan-instrument-func-entry-exit https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=06712fc68dc9843d9af7c7ac10047f49d305ad76 Therefore, we can re-enable GCC for KCSAN, and document the new compiler requirements. Signed-off-by: Marco Elver Cc: Martin Liska --- For anyone interested to try it out before GCC 11 is released, I'd recommend building a stable GCC 10 with the patches applied: git clone git://gcc.gnu.org/git/gcc.git && cd gcc git checkout -b gcc-10-for-kcsan releases/gcc-10.1.0 git cherry-pick \ 4089df8ef4a63126b0774c39b6638845244c20d2 \ ab2789ec507a94f1a75a6534bca51c7b39037ce0 \ 06712fc68dc9843d9af7c7ac10047f49d305ad76 ./configure --prefix --enable-languages=c,c++ make -j$(nproc) && make install --- Documentation/dev-tools/kcsan.rst | 3 ++- lib/Kconfig.kcsan | 3 ++- scripts/Makefile.kcsan | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/Documentation/dev-tools/kcsan.rst b/Documentation/dev-tools/kcsan.rst index ce4bbd918648..8fa0dd6c8614 100644 --- a/Documentation/dev-tools/kcsan.rst +++ b/Documentation/dev-tools/kcsan.rst @@ -8,7 +8,8 @@ approach to detect races. KCSAN's primary purpose is to detect `data races`_. Usage ----- -KCSAN requires Clang version 11 or later. +KCSAN is supported by both GCC and Clang. With GCC we require version 11 or +later, and with Clang also require version 11 or later. To enable KCSAN configure the kernel with:: diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index 3f3b5bca7a8f..3d282d51849b 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -4,7 +4,8 @@ config HAVE_ARCH_KCSAN bool config HAVE_KCSAN_COMPILER - def_bool CC_IS_CLANG && $(cc-option,-fsanitize=thread -mllvm -tsan-distinguish-volatile=1) + def_bool (CC_IS_CLANG && $(cc-option,-fsanitize=thread -mllvm -tsan-distinguish-volatile=1)) || \ + (CC_IS_GCC && $(cc-option,-fsanitize=thread --param tsan-distinguish-volatile=1)) help For the list of compilers that support KCSAN, please see . diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan index bd4da1af5953..dd66206f4578 100644 --- a/scripts/Makefile.kcsan +++ b/scripts/Makefile.kcsan @@ -6,7 +6,7 @@ ifdef CONFIG_KCSAN ifdef CONFIG_CC_IS_CLANG cc-param = -mllvm -$(1) else -cc-param = --param -$(1) +cc-param = --param $(1) endif # Keep most options here optional, to allow enabling more compilers if absence -- 2.27.0.290.gba653c62da-goog